Thursday 2:00 p.m.

At first glance, the man walking down Queen Victoria Street, in the heart of the City of London, looked no different to anyone else. He was a tall man, with neatly cut hair and an unremarkable face. He wore a black overcoat and carried a briefcase.

Nobody paid him any attention. If they had, they might have seen that his eyes were glazed and unfocused, as if he was awake and asleep at the same time.

He walked slowly, his briefcase swinging gently in his hand. He arrived at a large road junction and crossed a paved area where a statue of a horse and rider looked down on the busy scene below.

Without changing his pace, he pulled a flat black electronic device, about the size of a smartphone, from the pocket of his coat. He placed it against the side of his head. Tiny suckers shot out of it and attached the machine tightly against his temple. Small lights along its side flashed and it began to emit a series of beeps and tones.

The man stopped, put down his briefcase and shrugged off his overcoat, letting it drop to the ground. Then he swung the briefcase over his shoulder. As it moved, metal wires snaked out and whipped around him, transforming it into a kind of backpack. Panels on the back of it slid open, revealing a mass of circuits.

Next, the device attached to the man’s head opened. It slid a narrow visor across his eyes, masking them with shifting green digital displays.

By now, the man was getting funny looks frompassers-by. He didn’t take any notice of them. He crossed the road, his stride never changing, and entered the huge stone building that was the headquarters of the National Deposit and Finance Bank.

Inside, there was an enormous hall with a polished marble floor and a high, vaulted ceiling. Customers queued at cashier desks. Staff bustled here and there.

The moment the man strode in, he raised his arm. Dozens of tiny heat-seeking darts instantly fired from a tube hidden in the sleeve of his shirt. They spread out, moving at lightning speed. All the customers and most of the staff were hit within 1.7 seconds. They crumpled to the floor, unconscious.

The remaining staff, protected behind bulletproof screens, reached for the alarm buttons beside their desks. But before any alarm was pressed, the man’s backpack sent out a jagged arc of electricity. It hit the screens and they shattered with a deafening crash. The staff screamed and ducked. A second buzzing arc hit the alarm buttons and fried them until nothingremained but smoking wires. The overload surged on through the building’s electrical systems and burned them out.

The man stopped and turned. 4.9 seconds had passed since he walked in.

OBJECTIVE 1: DISABLE STAFF AND SECURITY – ACHIEVED

OBJECTIVE 2: PREVENT INTERFERENCE – BEGIN

He reached round and drew a bulbous, gun-like object from his backpack. He fired it and a large green ball shot out towards the twin glass doors through which he’d arrived. The ball splattered right in the centre, where the two doors met, then instantly set into a hard seal, preventing anyone else from entering the bank.

The man turned back. Crunching over what remained of the bulletproof screens, he headed for the vault at the far end of the hall.

The staff who’d been behind the screens were now cowering in a corner. One of them reached for her phone with trembling fingers. The movementwas detected by the man’s backpack and it beeped. Without breaking step, he swung round and fired another green glob at the phone. It was knocked to the floor and encased in a rock-hard shell, completely useless.

The shining steel door to the vault was large and round. To one side was a single massive hinge. On the other was the locking wheel and entry coder that controlled access.

The target sights on the man’s visor glowed, zooming in on the vault. He took a disc-like machine from his backpack and flung it towards the door as if it was a frisbee.

The magnetic disc clanged against the exact centre of the steel door. It began to spin, emitting a droning, howling sound, which grew louder and louder. The entire vault door started to shimmer, as sound vibrations pulsed through it. Suddenly, the metal buckled and burst and the door caved in, leaving shreds of metal around a gaping hole. The disc dropped to the floor and self-destructed in a ball of fire.

OBJECTIVE 3: TAKE ITEMS – BEGIN

The man stepped into the vault, taking care not to snag himself on the shredded steel. Inside were rows of safety deposit boxes set into the walls. He ignored them all and marched over to a series of metal crates clamped to the floor. He placed a thin device, no larger than a pencil, against the complex electronic lock on one of the crates. The lock suddenly flashed red, then deactivated, springing the crate’s lid open. Inside, neatly stacked, were bars of solid gold.

Meanwhile, police cars had blocked off the area outside the entrance to the bank. Sirens whooped and people craned their necks from behind lines of yellow and black tape marked “Do Not Cross”. A senior officer arrived and spoke to one of the constables gathered by the entrance.

“The doors are sealed?” he shouted. “With what?”

“We don’t know, sir.”

“Blow them apart!”

“We can’t do that, sir,” gulped the constable.“It’s a high-security bank. Those doors are built to withstand attack.”

“Then find another way in.”

“All the internal electrics are fried, sir. Security doors are on lockdown. We’ve got to bypass everything. We’ve got people working on it at the rear of the building, but it’ll take a few minutes.”

A woman in a smart business suit stood by, unnoticed. She smiled to herself. She was known only by her codename, Agent K, and she worked for a top-secret branch of the British secret service known as SWARM.

She spoke softly into the communicator tucked in her right ear. “Hive 2 to Hive 1, are you inside the bank?”

A calm, electronic voice answered her. “Affirmative.”

At that moment, the micro-robotic SWARM operatives were crawling up out of the bank’s staff toilet. They had been created using the most advanced technology in the world. Tough enough to survive extreme environments, packed with sensors and weapons, and programmed for high intelligence. They were ateam of undercover agents like no other.

There was a dragonfly, codenamed Chopper, coordinating their mission. Behind him came Nero, a scorpion, and Hercules, a stag beetle. After them came Sabre, a tiny mosquito, and a spider called Widow. Two more robots, Morph the centipede and Sirena the butterfly, were stationed outside the building.

“I’m glad we don’t have a human’s sense of smell,” said Hercules, scanning the toilet cubicle they had emerged into.

“Or a human’s size,” said Nero. “The bank robber won’t have planned for anyone getting in through the drainage system.”

The robots had been activated and rushed to the scene after SWARM’s advanced surveillance systems had intercepted police messages. Reports from one of London’s most secure banks about an armed intruder were something that needed investigating.

The five micro-robots scurried and flew across the white floor tiles and through the narrow gap at the bottom of the toilet door. They emerged into a short corridor, which led to the bank’s large main hall.

“Morph, anything to report?” signalled Chopper.

Morph the centipede had scuttled up the outside of the building, unseen, to a top corner of the main entrance where the police were positioned.

“My sensors show that the entrance has been sealed with a fast-setting organic polymer,” he transmitted. “Its origin is unknown. I’ve sent the data back to HQ.”

“Stay at your current location,” said Chopper. “Keep watch.”

“Logged,” said Morph.

“Sirena?” signalled Chopper.

Sirena the butterfly was at the back of the building, fluttering a few metres above street level. She was keeping watch on the police officers who were trying to open the rear exits. “No changehere,” she reported. “Deep scans confirm one attacker only. High levels of electronic activity. Humans inside are unharmed, but unconscious or in hiding.”

“He must be armed with something highly destructive,” said Morph.

The five robots inside the building made their move. Humans were in danger, so their mission priority was to stop the intruder as fast as possible.

They shot out into the main hall, dragonfly and mosquito buzzing high into the air, scorpion and beetle racing across the marble floor. The spider fired thin lines of web and swung herself in long, precise arcs.

The man in the vault was placing three heavy bars of gold into his backpack. That gold was worth around £600,000. It was all he’d been ordered to take, and all his backpack could carry.

He paused. Data streamed across the inside of his visor.

UNUSUAL MOVEMENT DETECTED!

REMOTE CONTROLLED CAMERAS?

DRONE WEAPONS?

PAUSECURRENT OBJECTIVE

NEW OBJECTIVE: DESTROY

He stood up straight, spun on his heel and stepped out of the vault.

“He knows we’re here,” said Nero.

“How?” said Hercules. “Our systems are shielded.”

Chopper’s advanced eye-lenses zoomed in on the man. His circuits analyzed and calculated. “He has a motion-detection pod.”

“To spot us, he must have technology above even military or secret-service specifications,” said Hercules.

Suddenly a box-like section jutted forward from the man’s backpack. It fired a miniature missile, which roared through the air towards Chopper and Sabre. The robots’ advanced flight systems whipped them aside just in time and the missile hit the high ceiling. There was an almighty bang and a flash of flame. A shower of stone fragments burst across the hall and clouds of dust billowed down.

Using the dust clouds as cover, Nero dashed over, while Sabre buzzed in a wide semi-circle. Sabre’s needle-like mouthparts loaded up a pellet, ready to inject.

The man’s backpack bleeped.

SMALL OBJECT AT FLOOR LEVEL

MINIATURE CAMERA OR SURVEILLANCE DEVICE SUSPECTED

NEW OBJECTIVE: DESTROY

As Nero shot forward, the man aimed a kick that sent the scorpion flying. Nero smacked into a nearby wall and dropped to the floor, upside down and motionless, his systems knocked into emergency shutdown.

“I’m going in,” said Sabre.

“Wait,” said Chopper. “It’s too dangerous! He spotted Nero despite the dust and we can’t have two agents down. Widow, distract him so Sabre can attack.”

Instantly, the spider dived out of the dust cloud, zipping along a microscopic thread. Sure enough, the man’s visor detected the movement. He swung round towards Widow. Sabre buzzed overhead.

The man twisted the barrel of his sealant-firing gun, adjusting its output. As Sabre dived from high above, aiming for the man’s neck, the gun was struck against the ground, pointing upwards. Its barrel suddenly opened and fat balls of glue fired out in all directions. Electronic components inside the balls were instantly detected by the SWARM.

“Evasive manoeuvres!” said Chopper.

The glue-balls snaked at high speed through the air, homing in on the robots, following the tiny changes in air currents that they made as they moved. Even the SWARM couldn’t move fast enough to avoid them. Sabre, barely three centimetres from his target, was hit first. The impact shot him across the room.

At last, Nero’s systems rebooted and he flipped himself over. “No damage,” he reported. Then a large ball of glue hit him squarely between hispincers. He was stuck fast.